Last weekend, service was shut down on the city's main Line 1 as crews worked to upgrade the 60-year-old signal system. The TTC's website said the "necessary signal work will result in a more reliable service".

Many commuters voiced their ongoing frustration with the quality of the city's subway line during the shutdown.

This morning entire subway system in #toronto shutdown #TTC problems. Perhaps this is the wake up call to finally fix city's transit issues

In the past the city has turned to the UK for advice on how to improve its subway infrastructure.

In a scoping report by UK Trade and Investment released in late 2013, the UK government targeted Canadian rail as a market potentially worth billions of pounds to the industry under the new EU-Canada Comprehensive Economic and Trade Agreement.